Bonding duct work.

N

nizak

Senior Member
Inspector is requiring ductwork and metal gas pipe in crawl space to be bonded.

In past jobs I have never been required to do this since the EGC from the furnace circuit sufficed.

He is saying that it could become energized and that the #14 EGC is undersized.

Is it acceptable to just bug onto the GEC conductor and hit both the black iron pipe and the sheet metal?

Thanks
 
Informational Note No. 1 to 250.104(B) makes it very clear that the code does not require duct work to be bonded.
Informational Note No. 1:
Bonding all piping and metal air ducts within the premises will provide additional safety.
Click to expand...
 
Side note: When I piped in my natural gas furnace the instructions stated stated to use a dielectric union. Of course my local plumbing supply did not have a 1/2 or 3/4" dielectric threaded black unions. ( had plenty of solder on copper to copper ) so went with a conventional union. I had my HVAC buddy install a guess its a coated canvas isolation piece between top of A coil and main duct work to reduce sound. Replaced old 14/2 AC cable with 12/2 MC cable and a #8 guage copper jumper between insulated duct work. Years ago I had to replace a section of 14/2 cloth covered NM cable that due to rubbing on duct work cut thru jacket and short out. Homeowner ran the wire tight to duct and made a 90 degree turn down a wall . During A CEU class the instructor brought up a good discussion. If a home had all non metallic piping and no garbage disposal would a metal sink have to be bonded.
 
garbo said:
Side note: When I piped in my natural gas furnace the instructions stated stated to use a dielectric union. Of course my local plumbing supply did not have a 1/2 or 3/4" dielectric threaded black unions. ( had plenty of solder on copper to copper ) so went with a conventional union. I had my HVAC buddy install a guess its a coated canvas isolation piece between top of A coil and main duct work to reduce sound. Replaced old 14/2 AC cable with 12/2 MC cable and a #8 guage copper jumper between insulated duct work. Years ago I had to replace a section of 14/2 cloth covered NM cable that due to rubbing on duct work cut thru jacket and short out. Homeowner ran the wire tight to duct and made a 90 degree turn down a wall . During A CEU class the instructor brought up a good discussion. If a home had all non metallic piping and no garbage disposal would a metal sink have to be bonded.
Click to expand...
Agree sinks & faucets should be bonded unless they have metallic piping. Ductwork as well unless it is bonded by the furnace EGC
 
garbo said:
Side note: When I piped in my natural gas furnace the instructions stated stated to use a dielectric union. Of course my local plumbing supply did not have a 1/2 or 3/4" dielectric threaded black unions. ( had plenty of solder on copper to copper ) so went with a conventional union. I had my HVAC buddy install a guess its a coated canvas isolation piece between top of A coil and main duct work to reduce sound. Replaced old 14/2 AC cable with 12/2 MC cable and a #8 guage copper jumper between insulated duct work. Years ago I had to replace a section of 14/2 cloth covered NM cable that due to rubbing on duct work cut thru jacket and short out. Homeowner ran the wire tight to duct and made a 90 degree turn down a wall . During A CEU class the instructor brought up a good discussion. If a home had all non metallic piping and no garbage disposal would a metal sink have to be bonded.
Click to expand...
It's not a system. Nope.
 
Eddie702 said:
Agree sinks & faucets should be bonded unless they have metallic piping. Ductwork as well unless it is bonded by the furnace EGC
Click to expand...
What would be likely to energize the sink or faucet? Since the source of the electric shock is likely portable electric appliances, the grounding of isolated parts increases the risk of someone getting a shock.
 
Obviously not NEC required but not as bad idea. A few years back we had a duct installer electrocuted by duct that cut into romex
 
garbo said:
Years ago I had to replace a section of 14/2 cloth covered NM cable that due to rubbing on duct work cut thru jacket and short out. Homeowner ran the wire tight to duct and made a 90 degree turn down a wall .
Click to expand...

Thats the argument the inspector makes for bonding gas pipe here, old existing cloth or even k&t wires that cross the piping chewed by rats etc. He also told me that in older parts of the city you can still find live capped gas lines above lighting fixtures.
 
gene6 said:
He also told me that in older parts of the city you can still find live capped gas lines above lighting fixtures.
Click to expand...
I have found capped gas lines in light boxes that are still live. Meaning that gas comes out when you remove the cap.
 
gene6 said:
Thats the argument the inspector makes for bonding gas pipe here, old existing cloth or even k&t wires that cross the piping chewed by rats etc. He also told me that in older parts of the city you can still find live capped gas lines above lighting fixtures.
Click to expand...
While working in an old house my friend purchased came across a live capped off gas pipe for on old ceiling gas light. Went down to the basement and disconnected the gas pipe and installed a cap. Several times saw a little capped off fitting on living room ceilings that appeared to feed gas light at one time.
 
gene6 said:
Thats the argument the inspector makes for bonding gas pipe here, old existing cloth or even k&t wires that cross the piping chewed by rats etc.
Click to expand...
He can make that argument but the NEC has no section that would require you to do so. If the owner of the building wants to pay for bonding that may enhance safety then they can do that but it is not a requirement.
 
don_resqcapt19 said:
What would be likely to energize the sink or faucet? Since the source of the electric shock is likely portable electric appliances, the grounding of isolated parts increases the risk of someone getting a shock.
Click to expand...
People have been known to drop hair dryers, toasters, hand mixers etc into a sink full of water or a bath tub. This is why you can't have receptacles next to tubs, showers, swimming pools or hot tubs. If your drop a two wire appliance in the water how does the breaker trip. Only if it's on a GFCI
 
You must log in or register to reply here.
Top